The text on his thesis paper is 36 font (about half an inch tall) double-spaced, and it’s still a struggle to read it, he said. He does what he can to get by reading emails or standard textbooks.

Since the fall 2012 semester, Taibleson has done all of his studying from home, where he lives alone. He receives help once a week and other times as needed from a longtime caregiver. He’s up every morning by 4:30 and makes it a point to hop on an exercise bike in his master bedroom for a half-hour to an hour each day. Until the arthritis on his left side became debilitating, he walked five miles a day for 25 years.

He said his college years have been fabulous.

“It developed friendships with kids and most of them are very, very nice and considerate, there are always a few jerks,” he said. “You have the faculty, the administration and the children and that became a good part of my life, especially after my wife died.”

Erika Daniels, assistant professor of literacy education at Cal State San Marcos, was one of Taibleson’s professors in the fall 2010 semester. She said he provided a role model to the other 28 students in the class because he epitomizes lifelong learning.

“He sat right in front, was at every single class session, and participated actively,” she said. “He constantly wants to keep his mind sharp and wants to learn about things he didn’t know about before.”

According to the Administration on Aging, the number of people 65 and older will reach about 72 million by 2030, up from 39.6 million in 2009. Dr. Dilip V. Jeste, director of the Stein Institute for Research on Aging at UCSD, said in an email this week that successful cognitive and emotional aging depends on keeping the mind active.

“Just as a treadmill makes the leg muscles stronger, learning can help in keeping the brain younger,” he wrote.

Jeste said going to school is great for socialization for seniors, helping stem loneliness and associated depression. It also helps them learn new things and teach some things − from their huge bank of experience − to the younger students as well.

Taibleson agrees, saying he spent so much of his latter years in school to improve his mind.

He cited his recently discovered “credo” by the American scientist Rosalyn Yalow: “‘The excitement of learning separates youth from old age. As long as you’re learning you’re not old.’”